diff --git a/RIGS/models.py b/RIGS/models.py
index 6c4c9c9c..75e641ec 100644
--- a/RIGS/models.py
+++ b/RIGS/models.py
@@ -10,6 +10,7 @@ import reversion
 import string
 import random
 from django.core.urlresolvers import reverse_lazy
+from django.core.exceptions import ValidationError
 
 from decimal import Decimal
 
@@ -348,6 +349,20 @@ class Event(models.Model, RevisionMixin):
     def __str__(self):
         return str(self.pk) + ": " + self.name
 
+    def clean(self):
+        if self.end_date and self.start_date > self.end_date:
+            raise ValidationError('Unless you\'ve invented time travel, the event can\'t finish before it has started.')
+
+        startEndSameDay = not self.end_date or self.end_date == self.start_date
+        hasStartAndEnd = self.has_start_time and self.has_end_time
+        if startEndSameDay and hasStartAndEnd and self.start_time > self.end_time:
+            raise ValidationError('Unless you\'ve invented time travel, the event can\'t finish before it has started.')            
+
+    def save(self, *args, **kwargs):
+        """Call :meth:`full_clean` before saving."""
+        self.full_clean()
+        super(Event, self).save(*args, **kwargs)
+
     class Meta:
         permissions = (
             ('view_event', 'Can view Events'),